Academy Award-winning screenwriter Paul Haggis has joined forces with a slew of Hollywood stars to demand freedom for renowned Iranian film director, Jafar Panahi and his artistic collaborator, Mohammad Rasoulof.

Last year Panahi, who has been a recipient of numerous awards and is also an outspoken supporter of the Green Movement and a government opposition, was sentenced to six years of confinement and received a twenty-year ban on leaving the country. Accused of “colluding with the intention to commit crimes against the country’s national security and propaganda against the Islamic Republic,” the 50-year-old filmmaker was also banned from making or directing any films, writing screenplays or giving any form of press interviews.

Both Panahi and Rasoulof are under house arrest while appealing the sentences.

But according to Haggis, who is campaigning on behalf of Amnesty International, Panahi and Rasoulof are victims of unjust silencing by the government.

“I just had to put myself in their place and say ‘boy, I wish someone would speak out if I was in prison for speaking my mind and banned from making films,’” Haggis told FOX411’s Pop Tarts. “I think it is our responsibility to speak out, especially for one of our colleagues. (As celebrities) we are just like any other citizens but we have a big voice, and we should use that voice.”

The delegation was initially told that they would not be allowed to directly hand the petition papers to a Mission representative at the Manhattan office building, with Haggis then telling a protocol officer in the lobby that he would not leave unless the Mission accepted the petitions, and tensions grew from there.

“The police came immediately and asked us to leave, I guess they decided we were criminally trespassing,” Haggis explained. “I went up there myself and just waited. They gave me a driver and I would not accept it. I had more than 20,000 signatures.”

As conflict escalated, police started clearing the lobby of protesters while Haggis signed postcards with Panahi’s photos on them. The Mission official was eventually instructed to keep the foot-high box of paper petitions once they were inspected.

Earlier, activists had gathered alongside the Hollywood-led delegation and chanted “Freedom for Panahi! Free All Prisoners of Conscience in Iran!”

The Iran Mission to the United Nations and the NYPD did not respond to our request for comment.

But, Haggis – who does not know the controversial filmmakers personally – is not sure if his efforts to free them will help or hinder the situation.

“We don’t know if anything will happen (as a result of the petition) as it’s very difficult. There’s always a question of whether a government like this digs its heels in when they get international pressure,” he said.

Nonetheless, Iranian-born actress Nazanin Boniadi, who was also part of the protest, is confident that their hard work will pay off.

“Amnesty did a campaign in Germany for Roxana Saberi in 2009 and we managed to receive worldwide 26,000 signatures in a petition. She was released,” Boniadi told us. “As artists, we have a very profound understanding of what self-expression means, and when someone’s freedom of expression is taken away from them it really touches us. We feel compelled to do something for our counterparts in places in the world where that freedom of expression is taken away.”